Process of extracting oils from coal-tar



H. H. COMBER AND J. W. STALKER. PROCESS OF EXTRACTING (ms FROM COAL TAR.APPLICATION BLED JUNE 17, I918.

3 327 2'71 a Patented Jan. 6, 1920.

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J N. Sfdker 7% UNITED STATES PATENT onruon.

HUBERT HENRY COMBER AND JAMES WRIGHT STALKER, 0F WINNIPEG, MANITOBA,

' CANADA.

PROCESS OF EXTRACTING OILS FROM COAL-TAR.

Patented Jan. 6, 1920.

Application filed June 17,1918. Serial No. 240,381

To all whom it may concern:

Be it known that we, HUBERT HENRY Corinna and JAMES WRIGHT STALKER, bothof the city of lVinnipeg in-the Province of Manitoba,,Canada, haveinvented certain new and useful Improvements in Processes of ExtractingOils from Coal-Tar, of which the following is a specification.

The invention relates to a process of ex tracting oils from coal tar bymeans of wood alcohol and has for. its principal object the provision ofa quick, expeditious and cheap process for separating the oils by usingwood alcohol and as a further object the reclaiming of the wood alcoholused in the process so that it can be used again to repeat the process,that is to say, reclaimed and regintroduced.

In order-that the process may be clearly understood 1 have showndiagrammatically the apparatus for carrying out the process and in thedrawing accompanying this specification.

The figure represents diagrammatically the aparatus used and the mannerin which the Various elements are connected.

In extracting the oils from coal tar the present practice has been toheat'the coal tar and obtain the various oils by distillation, the lightoils being given off at a temperature below 350 degrees F., the heavyoils between the temperatures of 350 degrees F., and 4-15 degrees F-.,the creosote oil between the temperatures of 4-15 degrees Fand 520degrees F. and anthracene at a temperature of 520 degrees F. and over,the

final product being pitch.

This is a-rather laborious and painstaking operation owing to the hightemperatures required and to the fact that the various oils come off atvarying temperatures.

According to our invention, the oils are separated by a cold process bythe use of wood alcohol which is put into the coal tar and mixed Wellwith it. The wood alcohol acts to cut the oils from the coal tar andafter a time the wood alcohol and oils are drawn ofi as a solution.

The solution so'obtained is next poured into a receptacle containingwater and mixed and the result .of this operation is that the woodalcohol and water combine and appear at the top of the Vessel, while theoils which are heavier sink to the bottom. The oils are at this timefree from any foreign substance and are drawn off from the vesselleaving the water and wood alcohol. .his completes the extraction of theoils from the coal tar and in order that the'wood alcohol can be used tocontinue carrying on the process we distil the water and wood alcohol byheating. I

The wood alcohol is driven ofi first as a vapor, the temperature beingproperly regulated, and after being condensed can be utilized forintroduction into a further quan-- tity of coal tar.

In referring to the drawing, 1 represents a vessel in which the coal tarcan be placed. This vessel is connected by a suitable pipe 2 to a mixingtank 3 provided with a drawofi ta Al and fitted with an agitator ormixer 5 which, in the present instance, is shown as provided with adriving pulley 6. A

valve 7 is introduced in the pipe 2. 8 represents a distilling vesselprovided with a fire pot 9 and connected with the mixing tank 3 .bymeans of the pipe 10.

11 represents a return pipe passing from the top of'the distillingvessel to the top of An entry pipe 14 opens to the top of the mixingtank and is provided with a suit-' able valve 15.

In carrying out is placed in the vessel water is poured into the vessel8, The valve 7 is then opened and a quantity of coal tar is allowed todrain down into the mixing tank. The wood alcohol is then introducedinto the tank through the pipe 14 and the agitator is then operated tothoroughl mix the coal tar and the Wood alcohol. hen the mixing has beenaccomplishedthe wood alcohol and oils combined are drained oil the tankthrough the pipe 10 into the distilling vessel where they are droppedinto the water. In this vessel the water and the wood alcohol separatefrom the oils and float on top of the oils thereby allowing the oilsto'be drawn off through the cook 13.

'A low fire is kept burning in the fire pot which will maintain atemperature of approximately degrees C. in the distilling vessel andthis acts to distil the wood alcohol from the water, the wood alcoholpassing out of the pipe 11 in the form of vapor 1 and a quantity of .sothe mixing tank and provided throughout and being condensed in the coil12 after which it is re-introduced into the tank and can be utilized tomix With a further quantity of coal tar drawn from the vessel 1.

While We have shown the equipment for carrying on this process, still itWill be understood that it is more diagrammatic than actual and is onlyherein shown to make clear how the process is carried on. In carryingout the process in the above manner it is necessary to draw off fromtime to time the pitch like substance accumulating in the bottom of themixing tank. This is done through the outlet 4:.

What We claim as our invention is The process of treating coal tartoseparate the oils therefrom which consists in thoroughly mixing byagitation in a vessel a quantity of Wood alcohol with a quantity of coaltar in the cold state, then draining 01f the upper layer of liquidcomprising the oils and Wood alcohol compound, then introducing theliquid drained off from the former vessel into a. further vesselcontaining Water to efi'ect the separation of the oils through thecompounding of the Water with the wood alcohol andfinally draining oilthe oils from the bottom of the latter vessel.

Signed at Vvinnipeg, this 11th day of May, 1918.

HUBERT HENRY COMBER. JAMES WRIGHT STALKER.

In the presence of G. S. RoxBUnGH, K. B. l/VAKEFIELD.

